This relates to systems in which power converters are used to charge electronic devices.
Power converter circuitry can be used to convert alternating current (AC) power into direct current (DC) power. AC power is typically supplied from wall outlets and is sometimes referred to as line power. Electronic devices include circuitry that runs from DC power. The DC power that is created by an AC-to-DC power converter may be used to power an electronic device. The DC power that is created may also be used to charge a battery in an electronic device.
Some electronic devices have input-output ports that include power and data lines. For example, some electronic devices have input-output ports such as Universal Serial Bus ports that include a pair of power lines and a pair of data lines. Universal Serial Bus (USB) connectors and other connectors may be used in ports such as these.
During normal operation of an electronic device, the USB port of a device may be used to convey power and data signals. For example, the USB port may be used to power a peripheral such as a printer or camera, to transfer data to and from an accessory, etc. Devices with batteries may be charged by drawing DC power from the power lines in the USB port. For example, a battery in a cellular telephone may be charged when the cellular telephone is connected to a USB port of a computer.
It can be convenient to charge electronic devices using USB ports on computers, but computer ports such as these are designed to supply only a limited amount of power. Faster charging can be achieved using stand-alone power converters. Stand-alone power converters can be provided with cables that have Universal Serial Bus plugs. This type of USB plug may be inserted into a Universal Serial Bus port on an electronic device, allowing the device to be charged from a wall outlet without involving a computer.
Although stand-alone USB chargers such as these may offer more charging power than the USB port on a computer, the capabilities of stand-alone USB chargers and other aspects of USB-based charging systems may be limited by industry standards.
It would therefore be desirable to be able to provide improved charging systems such as charging systems in which power is conveyed over input-output port paths such as Universal Serial Bus paths.